Hello, I recently noticed a fair amount of white discoloration on the interior of my first generation Steyr AUG A3. I was wondering if this might be normal wear-and-tear or something more severe. I noticed that all of the discoloration seems to appear around the gas-block and barrel, both of which get very hot during sustained firing. I have attached photos of the discolorations, excuse the potato-quality camera.

I was wondering if anyone else could compare it to one of their own Steyrs to see if the same discoloration exists. Here is another photo of the whiteness around the part where the barrel joins the upper receiver. I am worried that this may be a case of galvanic corrosion, at the discoloration only appears on the aluminum parts of the rifle and not on the steel. If it is, it may be my own fault due to a number of mods that I have made to the rifle.

The only other place this is seen is right at the inlet of the gas block on the inside of the upper receiver. This gives me hope that this is burnt-up oil or powder or some other residue. However, I worry that by changing out the charging handle, or swapping out the upper rail, I may have broken the anodizing seal that prevents the steel bolts from making electrical contact with the aluminum receiver. If there was any salt water or humidity, this would have created a galvanic cell, allowing the aluminum to corrode. I understand that this is usually a very rare occurrence.

I also made the immensely foolish decision at one point of using Graphite dry lubricant in parts of the rifle, largely because I didn't know nay better at the time. I have since made every possible effort to wash it out and switch back to petroleum-based lubricants.

It is interesting to note that the whiteness only seems to appear on areas that are exposed directly to extreme heat. The ring that holds the barrel in place I presume to be steel, and the aluminum around it is white, as well as in the interior of the aluminum tube behind where the gas block/pistol assembly would vent into.

Hoping this is something you have seen before and/or normal on Steyrs and not a case of severe corrosion. Any input would be appreciated.

I seriously doubt that graphite or even corrosion is your issue unless you live on a ship or in a salt mine. You'd be seeing issues on your steel parts long before that.
Are you seeing any scale or surface deformation beyond normal wear from areas that rub?

That aluminum housing looks like it was dyed green, or at least a type of black that was based on a green dye. What I suspect might be happening is that the dye is leaking out from under it's seal, or just breaking down.
Aluminum can be colored by letting it soak in dye after anodizing. The dye fills in various pores created by the anodizing. It can then be sealed by various methods, either by boiling or using a sealer. There are various reasons the dye can decide to fuck off or break down. UV radiation from the sun is notorious for bleaching colored aluminum parts.

>>106360> Graphite dry lubricant
I made the same mistake when I first got into guns, if you apply too much of that dry lube it will have that weird white stuff on the area you over apply the lube. For my AUG I went with the good old grease and it's working well so far.

I'd suggest do a thorough cleaning of your AUG and apply a different lube/grease on it. It seems there is more maintenance for dry lube than the gun itself.

>>106365Interesting, could you take some pictures?
Corrosion due to graphite on aluminum has always been one of those mythical things that is mentioned, but never seen. Prior to this thread I've not seen a single possible example in a gun.

Never used it myself, because honestly the only suitable place for it is a foosball table.

That is good to hear, as long as the weapon is disintegrating and it is just discoloration, I am fine with it. I also googles "White powder inside AR-15" to see if anyone else was having similar issues. Interestingly, two other people mentioned similar residue after firing American Eagle XM193 ammunition which, curiously enough, was the exact same ammunition I had been using earlier. Thanks for all of the input, I intend to give another cleaning or two and might email Steyr about the issue.